Richard Castle, Fanboy
by Known Unknowns
Summary: Castle's acting weird... even weirder than usual, actually. Beckett discovers that Castle is a Firefly fanboy. The real question is, can he convert her into a Browncoat?


**Richard Castle, Fanboy**

_A/N: Well, it's official: I'm obsessed with Firefly. So, naturally, in the wee hours of the morning I decided to put my 'what if Castle was a Firefly fanboy' idea into print. I didn't put this in the crossover section, mainly because it doesn't include any characters or settings from the show, just references._

_Disclaimer: I don't own Castle, Firefly, or Serenity._

* * *

The first time it happened, she didn't even really notice. She thought it was just Castle taking a dangerous and life-threatening moment, and trying to inject some humor into the situation, as being trapped in a closet in the house of a murder suspect was, undeniably, a rather sticky one.

They heard heavy footsteps outside. They had arrived at Kevin Goral's house with the intention to arrest him, having found evidence that proved beyond a reasonable doubt that he had murdered his brother Jason. They had stalked through the house, trying to find some sign of him, but Kevin had seemed to be absent.

"Oh, this is a bad idea," Castle commented worriedly. Beckett had just rolled her eyes.

"The big, scary murderer isn't going to get the jump on us, Castle."

Then they heard someone walk through the front door, which had been hanging wide open. That was followed by the sound of a shotgun being pumped. Castle's dark blue eyes had widened comically, and the next moment, she found herself shoved into an uncomfortably small and dark closet, Castle a breath away from her.

"Castle!" she whispered, irritation seeping into her voice. "Now we're pinned down! If he flings open this door and he's got a faster trigger finger than me, we're dead!"

Castle had stared at her for a long moment before gripping her shoulders, a look of absolute seriousness written across his face.

"We're not gonna die. We can't die, Beckett. You know why? Because we are so _very_ pretty. We are just too pretty for God to let us die," he told her, voice shaking.

Before she had a chance to ask what the hell he was talking about, the door burst open. Beckett had just enough time to launch out a leg at Kevin, who had appeared in the doorway, and sent him tumbling to the ground before he could get a shot off at him. She quickly scooped up the weapon, pointing her own pistol down at the man. "Kevin Goral, you're under arrest for the murder of your brother, Jason Goral. You have the right to remain silent. Anything you say can and will be used against you in a court of law..."

A few minutes later, Beckett was escorting Kevin to the police cruiser, Castle trailing close behind. As she shoved him roughly into the back, hands cuffed, she turned back to Castle. "Well, you were right about this being a bad idea," she commented. At this, a wide smile spread across Castle's face, giving him a boyish look.

"Thanks for sayin', sir," he said, before realizing he had inadvertently called Becket 'sir'. "Err, I mean _mam_."

At that point, she just shook her head, wondering if maybe the stress of working as a police consultant was starting to get to Castle.

* * *

Over the next week, she noticed more and more odd behavior from her partner. She had heard the word 'ain't' slip out of his mouth several times, which both confused and appalled her. Castle was a writer, for the love of God! She had never heard the man use an ounce of improper grammar in her life, and his sudden abandonment of this was unsettling, to say the least.

She had also heard him shout something that sounded like "Gorram!" at the top of his lungs when he had stubbed his toe on the edge of her desk, something that thoroughly puzzled her. Had he been trying to say goddamn? That didn't seem like Castle either, who generally didn't use language that coarse.

That night, they had been working late at the precinct. Castle had volunteered to make a pot of coffee for them all, and had made his way to the small staff kitchen. Beckett had gone in to ask him if he wanted to sit in on the interrogation of their next suspect when she had halted in the doorway, realizing that Castle was singing a tune.

"_Take my love, take my land, take me where I cannot stand_. _I don't care, I'm still free, you can't take the sky from me," _he sang as he began pouring the coffee out into separate mugs for Castle, herself, Ryan, and Esposito. "_Take me out to the black, tell them I ain't coming back. Burn the land and boil the sea, you can't take the sky from me."_

She didn't recognize the tune, and it didn't sound like something Castle would normally listen to. She found her self slightly amused, so she crossed her arms and continued to watch him without his knowledge from the doorway, a smirk playing on her lips.

"_Leave the men where they lay, they'll never see another day. Lost my soul, lost my dream, you can't take the sky from me. I feel the black reaching out, I hear its song without a doubt. I still hear and I still see, you can't take the sky from me," _Castle sang, bobbing his head slightly as he finished pouring the cups.

"_Lost my love, lost my land, lost the place I could stand. There's no place I could be, since I found - _Beckett!" he exclaimed as he turned around, cups in hand, and finally noticed her presence. "Uh - here's your coffee! Here, take it, nice and hot," he shoved the drink at her as smiled awkwardly, before promptly bolting out of the room.

_What the hell is going on with him?_

* * *

The next day, they had the intention of running a raid on a drug house, which was also harboring a drug dealer by the name of Bart Higgs, who they suspected to have at the very least been involved in the murder of one of his clients. Beckett carefully strapped on her bullet proof vest, and Castle mirrored her actions, pulling his 'writer' vest over his shoulders.

"Time for some thrilling heroics," he said with grin, rubbing the palms of his hands together.

The raid was successful, and later that night they had Bart Higgs in custody, under the charge of murder. They had found the murder weapon, a custom made straight razor, in Higgs' drug den.

With that, they had the night off. Castle invited everyone over for poker to celebrate. Beckett arrived early, a bag of chips tucked under her arm. She didn't bother knocking, as Castle had often told her "My home is your home, Beckett!" whenever she observed the polite custom.

However, that time, she really wish she would have knocked.

Castle was sitting on his couch, a large cardboard box in front of him on the coffee table. By the box were several small plastic dinosaurs, which he appeared to be having an unnaturally good time playing with. He gripped what seemed to be a stegosaurus in one hand, and an allosaurus in the other.

"Yes. Yes, this is a fertile land, and we will thrive. We will rule over all this land, and we will call it... 'This Land'." Castle said in a deep voice, making the stegosaurus bob up and down as he talked.

"I think we should call it, 'your grave'!" Castle muttered in a different tone, moving the allosaurus now.

"Ah! Curse your sudden but inevitable betrayal!" Castle said in the stegosaurus' voice. Beckett was starting to think Castle really was going off of the deep-end. Of course, he obviously didn't know she was watching him... his back was turned to her... _People do the strangest things when they're alone._

"Har har har! Mine is an evil laugh! Now _die_!" Castle launched the allosaurus at the stegosaurus, crashing them together repeatedly.

"Oh, no, God! Oh, dear God in heaven!" Castle whisper-screamed, seemingly lost in his make-believe dinosaurs.

"Castle?" Beckett called his name, unable to watch any longer. Castle turned in a flash, cheeks flushing.

"Oh! Beckett! Alexis was cleaning out her closet, and I was just, uh, looking through some of her old toys," he explained quickly, dropping the dinosaurs and shoving them off of the coffee table.

"Right," Beckett said slowly, setting the chips on the kitchen counter. "And you need to play with them because...?"

Castle paled. "Oh, you know, nostalgia," he said feebly, shrugging his shoulders with a nervous laugh and quickly changing the subject.

* * *

The final straw was three days later. Castle had been continuing to act incredibly strange, humming that mysterious tune and letting more 'ain't's, 'gorram's, and even an occasional 'rutting' slip, though she wasn't even half sure what the last one was supposed to imply.

It was late afternoon when Castle sank down across from her. She had been filling out paperwork for the past four hours, and her hand and eyes were starting to ache. Her car had broken down that morning, forcing her to take the bus to work. On top of that, she had been forced to chase a suspect four blocks earlier that day, and she had tripped at one point and skinned both of her knees before cuffing the guy.

It was a bad day, and she told Castle as much. His eyes had flared as he leaned forward on the desk, clasping his hands together.

"No, a bad day is when someone's yellin' spooks the cattle. Understand? You ever see cattle stampede when they got no place to run? It's kind of like a... a meat grinder. And it'll lose us half the herd," he said. He didn't seem to realize what had just popped out of his mouth until he saw the utterly perplexed look in Beckett's eyes. Beckett huffed out a breath, setting down her pen and glaring at Castle.

"Okay Castle - I'm done. What the hell is up with you? All these weird things you've been saying, the improper grammar, the nonsensical cuss words, you constantly humming or singing that stupid song, and the freaking dinosaurs... you're acting crazy!" she burst out, letting her irritation show through clearly. "Explain, _now_!"

Castle considered her for a second, apparently trying to figure out how to respond to her demand. He finally sighed, leaning his chin on his hand. "Beckett, have you ever heard of the TV show Firefly? The movie Serenity?"

She furrowed her brow at him. "No to both."

His eyes widened in indignation and shock. "After work tonight, come over to my apartment. I need to show you something."

At first, she was reluctant, but the pleading puppy dog look in his eyes broke her down. She relented, and agreed to come by his apartment shortly after work.

* * *

That night, Castle was waiting impatiently for her in his living room, remote control in his hand. "Come on, Beckett! We've got quite a night ahead of us!" he declared, excited by her arrival.

"Okay...?" she removed her coat and hung it by the door, making her way over to sit down next to Castle on the couch. Sitting by the TV were a stack of DVDs, all with the word 'Firefly' inscribed on the side. "Castle, what is this about?" she asked, still confused. He leaned back into the couch, pressing the play button on the screen.

"Tonight, my dear soon-to-be-Browncoat, we watch Firefly. You'll love the main character, he's drop-dead _gorgeous_..."

* * *

_One week later..._

Castle helped the injured woman to her feet. She had obviously been severely shaken up by her abduction by her estranged father, not to mention the deep gash in her side that she had been awarded when she tried to escape. He helped her into the ambulance that Beckett had dispatched to the warehouse the woman had been being held at. The EMT informed him that much longer, and she would have bled out. As the ambulance doors closed and it departed them, Castle turned to Beckett.

"Appears we got here just in the nick of time. What does that make us?" he asked her, a sly smile on his face, which Beckett returned.

"Big damn heroes, sir," she replied dutifully.

"Ain't we just."


End file.
